Front operated disconnect switch



Dec. 11, 1956 D. w. JOHNSON 2,773,955

FRONT OPERATED DISCONNECT SWITCH Filed Oct. 21., 1953 2 Sheets-Sheet lflcm/cdn. JZJUISOTL f/IS ATTORNE Y5 1956 D. w. JOHNSON FRONT OPERATEDDISCONNECT swmn 2 Sheets-Sheet 2 Filed Oct. 21, 1953 i 3 j INIENTOR.fitu/tZWJoiurSom Y QM &1, H/I/l TTOR IVE Y United States Patent FRONTOPERATED DISCONNECT SWITCH David W. Johnson, Newington, Conn, assignorto The Arrow-Hart & Hegeman Electric Company, Hartford, Conn., acorporation of Connecticut Application October 21, 1953, Serial No.387,407

13 Claims. (Cl. 200-73) This invention relates to electric switches.More particularly it relates to switches especially useful as disconnectswitches operable from the front but the invention is not limited tosuch use. in breaking electric circuits, it is frequently desirable tocause the contacts to separate initially with a slow motion for a shortdistance and thereafter to snap into fully open or off position. Thatdesire is achieved by a novel structural combination in this invention.

Therefore it is an object of this invention to provide an electricswitch operated from the front having a pro vision for slow separationof the contacts initially followed by a rapid break in the samedirection, the rapid break not being subject to a control of theoperator after the snapping action starts. I

Another object of the invention is to provide a switch of the foregoingtype which may be economically manufactured and will withstand longcontinued use and which will have a higher rating than switches normallyused in disconnecting electric circuit with a snapping action.

Other objects and advantages of the invention will appear as it isdescribed in connection with the accompanying drawings.

In the drawings:

Fig. 1 is a top plan view of a switch embodying the invention.

Fig. 2 is a longitudinal section view taken along line 22 of Fig. 1.

Fig. 3 is a fragmentary detail sectional view with a section being takenalong line 33 of Fig. 2.

Fig. 4 is a fragmentary detail view showing in bottom plan the operatingmechanism as appears when the bottom cover plate is removed.

Fig. 5 is a fragmentary detail view illustrating in bottom plan therelation of the actuating member and associated parts removed frombeneath the mounting plate, the parts being in the same position asthose in Fig. 4.

Figs. 6 and 7 are views similar to Figs. 4 and 5 respectively, butshowing the parts in an intermediate position between on and fully offposition.

Figs. 8 and 9 are views similar to Figs. 4 and 5 but showing the partsin fully off position. v

Fig. 10 is a fragmentary detail view showing in bottom plan the drivenmember of the snapping mechanism.

Referring to the drawings, the switch may be mounted in a base 11) madeof insulating material and provided with three connected centralrecesses 12 positioned transversely along the base and running fromfront to back. Connected with the three recesses 12 are three recesses13 on each side of the switch base containing terminal members 14,connected with which are pairs of fixed contact members such as 15 and16 extending from the terminal recesses 13 into the central contactrecesses 12. The terminal and contact members may be stamped as one partfrom sheet metal.

For engaging and disengaging the three pairs of stationary contacts 15and 16, three similar bridging contacts 25, 26 and 27 stamped from sheetmetal in bar form are mounted upon a contact carrier 20. The contactcarrier may conveniently be molded from insulating material with acentral rectangular spine 21 from the opposite sides of which extendarms 22 and 23 lying within the recess 12. In order to mount the movablecontacts resiliently upon the carrier, contact receiving recesses orpassages 24 are formed in the carrier, through which passages may extendthe bridge contacts 25, 26 and 27. Pressing the bridging contact towardthe fixed contacts are coiled compression springs 28, one end of each ofwhich presses upon the back of the movable contact member while theother end presses against the carrier so that when the carrier is movedinto switch-closed position, the bridging contacts will engage andautomatically adjust themselves against the fixed contact pairs.

In order to move the contact carrier 20, a small notch or recess 29 isformed in the bottom surface thereof to receive a lug 71 bent up atright angles from the end of an actuating member 70 which slides in aguideway 17 formed in the under side of the floor of the insulating base10. The actuating member or slide 70 may conveniently be stamped fromsheet metal in bar form with a recess or spring receiving aperture 74 inone end portion thereof. Said end portion is offset from the other endforming a shoulder 76 which is adapted to be engaged at proper time byan actuating pin 31 on the switch spindle 36 as will hereinafter be morefully described. The actuating member 70 is normally pressed by ahairpin coiled spring 72 toward open circuit position. The hair-pinspring may be seated in a deep spring receiving recess 78 in the underside of the floor of the insulating base with one end 77 pressingagainst the edge of the recess. The other end of the spring pressesagainst a spring anchor lug 73 struck down from the actuating member 7 0at one side thereof.

In order to overcome the biasing movement of the hair-pin spring 72, afinger or lug 59 (formed on the driven member 50, of the snappingmechanism as will hereinafter be more fully described) extends into theopening 74 in the slide 70 and is adapted to press against a coilcompression spring 75 located within one end of the opening 74. Theportion of the opening in which the spring 75 is located preferably isof rectangular shape and of width to receive the spring 75. Expansion ofthe spring 75 is limited by its abutment against the opposite ends ofthe rectangular portion of said aperture. As the actuating finger 59moves with the driven member 50 between the position shown in Figs. 5and 9 (which are equivalent to positions shown in Figs. 4 and 8) theactuating finger 59 moves from switch oil position as shown in Fig. 9wherein the finger is entirely out of the engagement with the spring 75into the position of Fig. 5 wherein the finger pressing against thespring 75 causes the slide 70 to move against the bias of the hair-pinspring 72. This movement causes the contact carrier to move from switchopen to switch closed position. Since the coil spring 75 is strongerthan the hair-pin spring 72, the bias of the latter is overcome.

The mechanism for manually operating the switch to cause separation ofthe fixed and movable contacts at first with a slow break and finallywith a snap action comprises a switch spindle 30 extending through theswitch base 10 from front to back. The spindle may be operated directlyby a handle 32 or in any suitable fashion. The opposite end of thespindle from that upon which the handle is mounted extends through astamped sheet metal mounting plate 18 fitted into a large recessed areaformed in the back or bottom surface of the insulating base 10. Thismounting plate is secured to the base and upon it is mounted themechanism actuated by the movement of the switch spindle except for theslide '76 which is located between the mounting plate and the switchbase in the longitudinal guideway in which the slide is located.

Fixedly mounted upon the bottom or end of the spindle 36 is a flatdisc-like sheet metal stamping forming the outer part 33 of the drivingmember of the snapping mechanism. At spaced points on the periphery ofthe driving disc 33 are radial teeth 34 and 35 which are adapted topositively engage a spring anchor lug 55 on a driven member 54)(hereinafter to be more fully described) so that in the event that thesnapping spring breaks, the switch can be operated manually "betweenopenand closed-circuit positions.

Secured to and turning as a unit with the outer disc member is aninnerstamped sheet-metal disc-shaped driving element 40. It is spaced fromthe outer disc 33 but secured thereto by arms 44, 45. These arms arebent up from. the plane of the inner disc 40 at diametrically oppositepositions into parallel relation with each other and with the spindleaxis. On;the ends of the arms 44 and 45 are fingers engaging in radialnotches or recesses in the periphery of the outer disc 33, the fingersbeing bent over to thus secure the outer and inner driving discs inspaced relation. Between these two discs is located a spring which iscoiled around the switch spindle with its ends extending substantiallyradially outward on opposite sides of the arm 45. Between the innerdriving disc 40 and the mounting plate 18 and loosely mounted upon theswitch spindle 30 is a driven stamped sheet-metal disc having a radiallyextending arm or lug 55 bent up to lie parallel to the axis of theswitch spindle outside the arm 45 and in alignment therewith. Theextending ends 36a and 36b of the snapping spring 36 thus engageopposite sides of both the driven arm 55 and the driving arm 45. Whenthe driving member is rotated as a unit with the switch spindle 30, thearm 45 pressing against one end or the other of the spring 36 tends tocarry the lug 55 and its disc along with it.

In order to hold the driven disc 50 against movement until the springhas been sufiiciently stressed to cause snapping action, and also untilthe spindle has moved sufficiently to cause opening or initialseparation of the fixed and movable contacts, there are provided a pairof spaced pivotally-mounted stamped sheet-metal latch arms or levers 61and 60. These levers are mounted upon the mounting plate 18 by pivotpins, 66and 67 respectively located adjacent opposite edges of the.mounting plate, each pin passing through an end of a lever. Formedv onthe opposite end of each leverare noses 62 and 63 respectively which areadapted to engage in notches 53 and 54 formed in the periphery of. thedriven member 50. The notches are spaced apart around the periphery sothat the nose 62 will enter into the notch 53 in the open position ofthe switch while the nose 63 will enter into the notch 54 in the closedposition. For biasingthe noses against the periphery of the driven disc50, a coiled tension spring 68 is stretched between the latch levers 6t)and 61, its ends being connected to lugs struck up out of the surface ofeach of the latch arms. In order to cause the noses 62 and 63 todisengage from the notches 53 and 54 respectively, a portion of each ofthe levers is bent out of the plane thereof into the plane of the innerdriving disc 40. These portions 64 and 65 respectively are adapted tofunction as cam followers, for camming portions 41 and 42 formed uponthe driving disc 44). The cam portions 41 and 42 are radial enlargementsspaced apart and lying upon opposite sides of the securing arm 44 inposition so that when the driving disc has been rotated a predetermineddistance, the cam portion 41 will engage the follower portion 64' of thelever 66 or the cam portion 42 will engage the follower portion 65 ofthe latch lever 61. After such engagement, continued rotation of thedriving disc 40 will cause the nose of the latching lever toleavethenotch in thedriven disc50. At

that time the arms 36a and 36b of the snapping spring 36 will have movedapart due to the movement of the arm 45 while the arm 55 remainsstationary. Thus as soon as the nose is disengaged from the notch, thedriven member will be snapped, by force of the snap spring, from theposition it had previously occupied into the new position, i. e., fromthe position of Fig. 4 to the position of Fig. 8 or vice versa.

As the switch spindle is rotated in switch-opening direction, itsinitial movement is transmitted to the slide 70 by engagement of theradial pin 31 extending therefrom with the shoulder 76 of the slide.Assuming that the parts are on the positions of Figs. 4- and 5, theoperation may be observed by referring to Figs. 6 and 7 in comparison toFigs. 4 and 5. In Figs. 6 and 7 the spindle has rotated about 15 or 20degrees and the pin 31 now has come into engagement with the shoulder76. During the next few degrees of movement of the spindle, the pincauses the slide to move from the dotted position to the full lineposition of Fig. 7, that is to move longitudinally approximately fromthe dotted line 0-0 to the dotted line dd. This movement of the slide istransmitted by its lug 71 to the contact carrier 20 which in turn causesthe bridging contacts to slowly separate from the fixed contacts a verysmall distance. This slow initial separation of the contacts as willreadily be understood by those familiar with switch operation iseffective in suppressing arcs incipient upon contact separation.

After that slow initial movement, continued rotation of switch spindle30 will cause engagement of the cam 42 with the follower portion 65 ofthe latch lever 61. As this cam continues to press against the followerportion 65, the latch lever has its nose 63 forced out of the notch 54with the result that the driven member 50 is snapped from the positionof Fig. 4 to the position of Fig. 6.

During the rotation of the switch spindle from the position of Fig. 5 tothe position of Fig. 7, the actuating finger 59 on the driven member 50remains stationary but the slide is moved to the full line position ofFig. 7. As a result, the spring 75 is compressed as will be observed inFig. 7 during the initial slow opening movement of the slide 70. Afterthe cam 42 engages the follower portion 65 of the latch lever 61 andcauses the nose 63 to move out of the slot 54 of the driven member, thedriven member is then free to move, which it does with a snap actionunder the force of a spring 36. This snap movement causes the actuatingfinger 59 to move from the position of Fig. 7 to the position of Fig. 9permitting the spring 75 to expand. The snapping action is accomplishedby the movement of the actuating finger 59. In moving from the positionof Figs. 5 and 7 to the position of Fig. 9, it strikes against the endof the slot 74, thus causes the slide 70 to move with a snap motion. Thesnapping is particularly etfective because at the time that the finger59 strikes the end of the opening 74, the finger is moving at a highrate of speed. The hair-pin spring 72 is provided mainly for moving theslide to open circuit position in case the snapping spring for anyreason should break or become disabled. The hair-pin spring is free tomove the slide whenever the nose 63 is disengaged from notch 54.

The springs 28 press against the movable contact members holding them inresilient engagement with the pairs of fixed contacts when the contactcarrier is in closed circuit position. Those springs react however totend to move the contact carrier from closed circuit position. Hence thecombined pressure of the contact springs must be overcome by thepressure of a slides coil spring 72 through which the effect of theposition of the snapping is transmitted to the slide and contactcarrier. It is therefore necessary for the spring. 75.to be strongerthan the combined forces of the contact. springs. I

From the foregoing it will be apparent that I have provided a novelstructural combination of parts for electric switch particularly usefulas a disconnect switch which is operable from the front but which is notlimited to use as a disconnect switch. The structure provides formovement of the bridging contact by a carrier which moves to and fro, orin a straight line, to cause engagement with or disengagement from apair of stationary contacts; moreover the movement of the bridgingcontact in opening direction is initially with a slow motion to cause aslow break which is followed by movement of the contacts in the samedirection at a more rapid motion with a snap action. The slow break isunder control of the operator to the extent that if he moves the handleslowly, he can control the slow-breaking action. But, if he moves thehandle as is usually the case with a uniform and continuous motion untilthe snapping action takes place, the slow break will nevertheless bebrought about in the desired manner.

Modifications within the scope of the invention will occur to thoseskilled in the art. Therefore the invention is not limited to thespecific form illustrated and described.

What is claimed is:

1. In an electric switch, fixed and movable contacts, a movable contactcarrier, manual operating means, means moving with the manual operatingmeans to positively move said carrier causing slow separation of themovable from the fixed contacts, snap-action means operable by saidmanual operating means and becoming effective automatically on continuedmovement of said manual operating means after said slow separation thento continue movement of said carrier in the same direction with a snapmotion, and means causing said carrier to move with a snap actionuninterruptedly on reverse operation of said manual operating means.

2. In an electric switch, fixed contacts and movable contacts, a contactactuating slide member for moving said contacts rectilinearly into andout of engagement, and means to cause said disengagement initially witha slow motion and then to continue with a snap motion in the samedirection comprising a rotary shaft, and snap acting mechanism, means onsaid shaft positively operating said slide in contact separatingdirection, and means between said slide member and snap-mechanism tocause the latter to become effective only after contact separatron.

3. In an electric switch, fixed and movable contacts, an actuatormovable in an undeviating path to and fro for moving said movablecontacts, a shaft, means on said shaft and moving therewith and engagingsaid actuator when said shaft moves in one direction to cause slowseparation of said fixed and movable contacts, and other means operableby the shaft after predetermined rotation and when said contacts areseparated to complete the movement of said actuator with a snap motion.

4. In an electric switch as claimed in claim 3 having means holding saidother means stationary during the slow separation of said contacts.

5. In an electric switch as claimed in claim 3 having means turning withsaid shaft to disable said holding means after said slow separation ofthe contacts.

6. In an electric switch as claimed in claim 3 having an extension onsaid other means having a resilient lost motion connection with saidactuator permitting movement into contact separating direction of saidactuator while said other means remains stationary.

7. A switch as claimed in claim 4 wherein the holding means comprises apivoted latch arm engageable with said other means.

8. In an electric switch, fixed and movable contacts, a slidableactuating member for moving said movable contact, rotary snap actingmechanism, a spindle independent of said actuating member, means totransmit the action of said snapping mechanism to said movable contact,and means operated by said spindle to cause movement of said slidablemember slowly to separate said contacts before said snapping mechanismbecomes effective.

9. A switch as claimed in claim 8 wherein the snap action mechanism haslatching means which is normally engaged in both at-rest positions ofthe switch, and means to trip said latching means after a predetermineddegree of rotation of the snapping mechanism.

10. In an electric switch, fixed and movable contacts, a slidableactuating member for moving said movable contact, rotary snap actingmechanism, a spindle independent of said actuating member, means totransmit the action of said snapping mechanism to said movable contact,and means operated by said spindle to cause slow movement of saidslidable member independently of said snapping mechanism, and meansoperated by rotation of said spindle to cause said snapping mechanism toact after the contacts have separated.

11. In an electric switch, fixed and movable contacts, a slidableactuating member for moving said movable contact, rotary snap actingmechanism, a spindle independent of said actuating member, means totransmit the action of said snapping mechanism to said movable contact,and a member moving unitarily with said spindle to cause slow movementof said slidable member independently of said snapping mechanism, saidmeans to transmit the snap action including a lost motion connectionpermitting separation of the contacts before said snapping mechanismbecomes effective.

12. In an electric switch, fixed and movable contacts, a slidableactuating member, driven means to move said slidable member, snap actionmeans to drive said driven member, a spindle to operate said snap actionmeans, means turning with said spindle to move said actuating member andseparate said contacts slowly before said snap acting means becomeseffective, and means turning with said spindle to positively move saiddriven means if said snapping mechanism becomes disabled.

13. An electric switch as claimed in claim 12 having latching means todelay action of said snapping means until said spindle has rotated apredetermined distance, and means rotating with said spindle to releasesaid latching means upon said predetermined rotation of the spindle.

References Cited in the file of this patent UNITED STATES PATENTS1,354,758 Kellner Oct. 5, 1920 2,068,713 Schellenger Ian. 26, 19372,163,919 Siegel June 27, 1939 2,625,619 Rigert Jan. 13, 1953 FOREIGNPATENTS 499,496 Great Britain Jan. 24, 1939

